Tanks are usually refilled by simple pouring. However, when the liquid is one that has a strong odor or is dangerous to health, the refilling must take place so that as much as possible vapors cannot escape. An example of this is the refilling of the liquid that is used in an SCR (selected catalytic reduction) process in diesel engines. This process is also known as “Bluetec.” The liquid that is used in this case has the trade name “AdBlue.” It is a 32.5% aqueous urea solution. The process is used to reduce the NOx fraction in exhaust gas and to convert nitrogen oxides to nitrogen and water. The fluid connection device used during tank refilling must be able to be made economically so that it can be discarded together with the canister from which the liquid is refilled.